From the end of the 17th century to the French Revolution, numerous diocesan breviaries and missals were published. Their authors often began their work with the recomposing of their calendar. To achieve this goal, they adopted unanimously several principles: priority accorded to local saints, restriction of "roman" saints, suspicion against doubtful saints... However, their strong willing seems to be contradicted with the case of the saints invoked in the Canon Missae. Despite their integration to the most sacred part of the Eucharistic ritual, these saints did not have legends consistent with the hagiological criteria assumed by the authors of these calendars. This paper aims to analyse their manners in resolving the dialectic tension between tradition, faith and historical criticism involved by the ambiguous epistemological status of these saints.